摘要:
In one aspect, the disclosure relates to calcium-free aluminum-based cement formulations designed for applications under supercritical conditions and in corrosive environments. In an aspect, alkali activation of aluminum hydroxide at high temperatures leads to the formation of mineral phases stable under supercritical and superhot conditions. In another aspect, these include, but are not limited to, crystalline phases of boehmite and paragonite and, optionally, a minor vlasovite phase. In yet another aspect, the compositions and articles made therefrom, such as geothermal well sheaths, are stable under the extreme conditions, and water-fillable porosity and mechanical properties of these cement formulations persist through super-critical exposure.
摘要:
A well cement composite and a method for making a well cement composite includes a mixture of calcium aluminate cement (CAC) and fly ash cenospheres (CS) in a weight ratio of from 30:70 to 80:20 CAC to CS; sodium metasilicate (SMS) in an amount of from 1 to 10% of the total weight of the mixture of CAC and CS; polymethylhydrosiloxane (PMHS) in an amount of from 0.5 to 6.0% of the total weight of the mixture of CAC and CS; and water in a weight ratio of from 0.5:1.0 to 1.2:1.0 of water to CAC and CS.
摘要:
A first circumferential wall disposed in a circumference of partition walls has no interface with the outermost circumference partition wall in a circumferential portion constituted by the partition walls whose wall thickness is larger than that of a central portion constituted by the partition walls in a central region. A maximum thickness of a total of the first circumferential wall and a second circumferential wall disposed to surround an outer side of the first circumferential wall is 1.2-3.0 mm, a difference between the maximum thickness and a minimum thickness of the total is 0.2-1.5 mm, and there is satisfied a relation, 0.5≤(TB−TA)×SB/SA×100(%)≤9.0 in which TB and TA indicate average thicknesses (μm) of the partition walls in the circumferential and central portion respectively, and SB and SA indicate areas (cm2) of the circumferential portion and the honeycomb structure in the cross section respectively.
摘要:
A porous material includes aggregates, and a bonding material bonding between the aggregates and including cordierite as a main component, and surfaces of three-phase interfaces in which the aggregates, the bonding material and pores intersect are smoothly bonded. Furthermore, in the porous material, the bonding material may include at least one additive component selected from the group consisting of strontium, yttrium, and zirconium, and a bending strength of the porous material is 5.5 MPa or more, or a honeycomb bending strength of a honeycomb structure using the porous material may be 4.0 MPa or more.
摘要:
There is disclosed a silicon carbide porous material having a high thermal shock resistance. The silicon carbide porous material of the present invention includes silicon carbide particles, metal silicon and an oxide phase, and the silicon carbide particles are bonded to one another via at least one of the metal silicon and the oxide phase. Furthermore, the oxide phase includes a parent phase, and a dispersion phase dispersed in the parent phase and having a higher thermal expansion coefficient than the parent phase. Here, a lower limit value of a content ratio of the dispersion phase in the oxide phase is preferably 1 mass %, and upper limit value of the content ratio of the dispersion phase in the oxide phase is 40 mass %. Furthermore, it is preferable that the parent phase is cordierite and that the dispersion phase is mullite.
摘要:
A porous ceramic honeycomb article includes a primary cordierite phase and an intercrystalline glass phase. In an as-fired condition, the porous ceramic honeycomb article exhibits microcrack parameter Nb3≦0.06 and an as-fired E500° C./E25° C. ratio ≦0.99. The article exhibits a coated microcrack parameter Nb3≦0.14 and a coated E500° C./E25° C. ratio ≦1.06 after the porous ceramic honeycomb article has been washcoated and calcined at a temperature of 550° C. After the article is exposed to a thermal treatment at a temperature ≧800° C. following washcoating and calcining, at least a first portion of the porous ceramic honeycomb article has a first treated microcrack parameter Nb3≧0.18, and a first treated mean coefficient of thermal expansion of not more than 12×10−7/° C. over a temperature range of 25° C. to 800° C. Methods of forming the porous ceramic honeycomb article are also disclosed.
摘要:
There is disclosed a silicon carbide porous material having a high thermal shock resistance. The silicon carbide porous material of the present invention includes silicon carbide particles, metal silicon and an oxide phase, and the silicon carbide particles are bonded to one another via at least one of the metal silicon and the oxide phase. Furthermore, the oxide phase includes a parent phase, and a dispersion phase dispersed in the parent phase and having a higher thermal expansion coefficient than the parent phase. Here, a lower limit value of a content ratio of the dispersion phase in the oxide phase is preferably 1 mass %, and upper limit value of the content ratio of the dispersion phase in the oxide phase is 40 mass %. Furthermore, it is preferable that the parent phase is cordierite and that the dispersion phase is mullite.
摘要:
A packaged concrete additive includes ground, expanded perlite with a volume weighted mean particle size of approximately 10-100 μm. The perlite optionally includes at least one additional component to improve workability and compensate for the natural tendency of expanded perlite to absorb water from the concrete mix. The additional component can include: water; a superplasticizer such as polycarboxylates, naphthalene sulfonate, and melamine sulfonate; or a hydrophobic compound, such as salts of fatty acids, fatty acids, silanes, and siloxanes. The additive is a flowable powder and for convenience of use it is packaged in a bag that can be directly added to the concrete batch and disappears on mixing. Concrete containing this additive displays superior properties to conventional concrete. Expanded perlite is a readily available raw material and the finished concrete is suitable where high strength structural concrete must withstand high temperatures.
摘要:
A packaged concrete additive includes ground, expanded perlite with a volume weighted mean particle size of approximately 10-100 μm. The perlite optionally includes at least one additional component to improve workability and compensate for the natural tendency of expanded perlite to absorb water from the concrete mix. The additional component can include: water; a superplasticizer such as polycarboxylates, naphthalene sulfonate, and melamine sulfonate; or a hydrophobic compound, such as salts of fatty acids, fatty acids, silanes, and siloxanes. The additive is a flowable powder and for convenience of use it is packaged in a bag that can be directly added to the concrete batch and disappears on mixing. Concrete containing this additive displays superior properties to conventional concrete. Expanded perlite is a readily available raw material and the finished concrete is suitable where high strength structural concrete must withstand high temperatures.
摘要:
Disclosed are ceramic bodies comprised of composite cordierite aluminum magnesium titanate ceramic compositions and methods for the manufacture of same.